1. Field of the Invention
This invention relates generally to disk memory drives and particularly to disk drives having increased storage capacity because of reduction in disk spacing to increase the number of disks in a given disk stack height.
2. Description of the Prior Art
Higher disk memory storage capacities are being required in applications in which increased disk memory space or volume is not available. Increasing the track density is not a presently viable approach to increasing the memory storage capacity because of problems encountered in reducing the size of the recording elements of magnetic heads, both from the point of view of magnetic head fabrication and magnetic flux control during the recording of the servo and data fields.
Efforts to meet the need for increased data storage in limited or reduced space in disk drives, have resulted in designs in which the axial spacing of the memory disks is being reduced. There are physical limits to size reductions in magnetic heads, as noted above, while still retaining functional utility and reliability. There are also physical limits to size reductions in the arms of armstacks which carry the magnetic heads and in their attachment supports, while still maintaining the arm strength and arm stability required to properly move and position the heads. The result is that clearance between the armstack structure projecting between the adjacent disks and the surfaces of these disks is reduced.
In presently known prior art disk/armstack designs in disk drives, the arms of the armstack and the heads are stacked in vertical alignment. Reductions in the space between the surfaces of the disk to 0.120 inches and less, negate the use of such an armstack design. Even if the heads and arms could be fitted between the disk surfaces in vertically aligned positions, the spacing would be too close to be practical. Shock forces due to handling could easily damage disk surfaces, and slight abnormalities in the roll or pitch attitudes of the head in flight, or in elevation of the head above the disk surface, could cause collision between stacked head supports at their extremities and head crashes on disk surfaces, with catastrophic results.